I recently finish my degree in Electrical Engineering.  It got me to
think one night, that it is amazing what music can be.  it only consists
of 12 notes (including semitone).  And within only the combination of these
12 pitches, composer can create infinite number of music.  In physics, to
pinpoint the exact location of a particle, you'd need 4 information; x,y,z
(space coordinate) and t(time).  In music to describe a melody/tune, you're
not only required to describe its space(what notes to play) and time (when
to play) coordinates, but also you need to specify the duration of a note
played, how fast to switch to another note, how loud the note should be
played and so on.  It is hard enough to imagine the fourth dimension in
physics.  It is possible to have more than 4 dimensions in theoritical
physics (metaphysics?).  Imagine adding extra dimensions to the music (more
than 12 notes?) in metamusic..this would pose extra variables to metamusic
composer.  imagine what it would sounds like.

b.